Heatable vehicle windows are known in the art. For example, see U.S. Pat. Nos. 5,434,384 and 4,782,216, the disclosures of which are hereby incorporated herein by reference. Heatable vehicle windows typically include first and second conductive bus bars in electrical communication with a transparent conductive coating including an electroconductive layer. The electroconductive layer generates heat when electric current passes therethrough. Current is typically supplied to the electroconductive layer via a pair of bus bars. In such a manner, snow and ice may be melted from vehicle windows such as windshields, backlites, sidelites, and/or the like. Windows may also be defogged in such a manner.
FIG. 1 is a side cross-sectional view of a peripheral portion of a conventional heatable window at a point where an external connection is made. The laminated window includes glass substrate 1, glass substrate 2, conductive bus bar 3 provided on the interior surface of substrate 2, a polymer inclusive interlayer (e.g., of PVB) 4 sandwiched between substrates 1 and 2, and external electrical connector 5 which is electrically connected to bus bar 3 via conductive solder 6. In manufacturing the vehicle windshield of FIG. 1, conductive connector 5 is adhered to bus bar 3 via solder 6 before substrates 1 and 2 are laminated to one another via interlayer 4. In other words, connector 5 is attached to bus bar 3 before interlayer 4 is placed thereover. After interlayer 4 is placed over connector 5 and solder 6, the substrates 1 and 2 are laminated to one another via interlayer 4.
Unfortunately, it may often be undesirable to adhere connector 5 to bus bar 3 before lamination of the two substrates to one another. For example, when this is the case, a vacuum-type lamination apparatus must often be used to laminate substrates 1 and 2 together. This can effectively limit the way in which lamination can be conducted, thereby leading to potential increases in capital expenditure.
In view of the above, it will be apparent to those skilled in the art that there exists a need for a more efficient bus bar connector interface structure in a laminated window, and corresponding method of manufacturing the overall vehicle window.